Compliant wafer probe assembly

ABSTRACT

Aspects of the invention include a wafer test device with a conformal laminate and rigid probes extending from the laminate to form an electrical connection with a microcircuit under test. The wafer test device also includes a spring plate on a side of the laminate that is opposite a side from which the rigid probes extend. The spring plate includes a conformal inner frame and a rigid outer frame. The laminate is attached to the inner frame of the spring plate.

BACKGROUND

The present invention generally relates to wafer testing, and morespecifically, to a compliant wafer probe assembly.

A wafer is a semiconductor layer used for the fabrication of integratedcircuits. The wafer serves as a substrate for microcircuits ofmicroelectronic devices that are built in and on the wafer and that makeup the integrated circuits. During fabrication, wafer testing isperformed to identify any functional defects in the microelectronicdevices. A probe device that can be referred to as a wafer probe is usedto perform automated testing. For electrical testing, a set of contactsor probes of the probe device are held in electrical contact withcontact points or solder bumps of the microelectronic devices of eachmicrocircuit in turn.

A test apparatus has electrical contact to the microcircuit under testthrough the wafer probe. The test apparatus controls test patterns thatare implemented on the microcircuit under test and assesses resultingbehavior of the microcircuit to determine if the microcircuit passes thetests. Once testing is completed, individual integrated circuits areobtained through a process referred to as dicing. The dicing separateseach microcircuit as a die which is then packaged as an integratedcircuit.

Complete and secure electrical contact between each solder bump of themicrocircuit and each corresponding probe of the probe device isnecessary for accurate testing of the microcircuit. This contact can bechallenged by non-planarity in the landscape of the solder bumps that isnot matched by the probes of the probe device.

SUMMARY

Embodiments of the present invention are directed to a compliant waferprobe assembly. A non-limiting example wafer test device includes aconformal laminate and rigid probes extending from the laminate to forman electrical connection with a microcircuit under test. The wafer testdevice also includes a spring plate on a side of the laminate that isopposite a side from which the rigid probes extend. The spring plateincludes a conformal inner frame and a rigid outer frame. The laminateis attached to the inner frame of the spring plate.

The wafer test device also includes an interposer on the side of thelaminate that is opposite the side from which the rigid probes extend.The interposer includes a pin portion within a frame from which floatingpins extend.

The wafter test device additionally includes an elastomer between thelaminate and the interposer. The elastomer may be formed as two or morecomponents. The elastomer supports conformity of the laminate tonon-planar regions of solder bumps on the microcircuit under test.

Other embodiments of the present invention pertain to a method ofassembling a wafer test device and include assembling a conformallaminate with rigid probes extending from the laminate to form anelectrical connection with a microcircuit under test. The method alsoincludes arranging a spring plate on a side of the laminate that isopposite a side from which the rigid probes extend. The spring plateincludes a conformal inner frame and a rigid outer frame. The laminateis attached to the inner frame of the spring plate.

An interposer is disposed on the side of the laminate that is oppositethe side from which the rigid probes extend. The interposer includes apin portion within a frame from which floating pins extend.

An elastomer is disposed between the laminate and the interposer. Theelastomer supports conformity of the laminate to non-planar regions ofsolder bumps of the microcircuit under test.

Additional technical features and benefits are realized through thetechniques of the present invention. Embodiments and aspects of theinvention are described in detail herein and are considered a part ofthe claimed subject matter. For a better understanding, refer to thedetailed description and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The specifics of the exclusive rights described herein are particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe embodiments of the invention are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1 depicts a wafer and corresponding wafer test components includinga wafer probe assembly according to one or more embodiments of theinvention;

FIG. 2 is an exploded view of aspects of the wafer probe assemblyaccording to one or more embodiments of the invention;

FIG. 3A is a cross-sectional view of aspects of the wafer probe assemblyaccording to one or more embodiments of the invention;

FIG. 3B is a cross-sectional view of aspects of the wafer probe assemblyaccording to one or more embodiments of the invention;

FIG. 3C is a cross-sectional view of aspects of the wafer probe assemblyaccording to one or more embodiments of the invention;

FIG. 3D is a cross-sectional view of aspects of the wafer probe assemblyaccording to one or more embodiments of the invention;

FIG. 4A illustrates an arrangement of the elastomer according to anexemplary embodiment of the invention;

FIG. 4B illustrates an arrangement of the elastomer according to anexemplary embodiment of the invention;

FIG. 4C illustrates an arrangement of the elastomer according to anexemplary embodiment of the invention;

FIG. 5 illustrates an exemplary scenario that benefits from the waferprobe assembly according to one or more embodiments of the invention;and

FIG. 6 is a block diagram of aspects of the test apparatus used with awafer probe that includes an elastomer according to one or moreembodiments of the invention.

The diagrams depicted herein are illustrative. There can be manyvariations to the diagrams or the operations described therein withoutdeparting from the spirit of the invention. For instance, the actionscan be performed in a differing order or actions can be added, deletedor modified. Also, the term “coupled” and variations thereof describeshaving a communications path between two elements and does not imply adirect connection between the elements with no interveningelements/connections between them. All of these variations areconsidered a part of the specification.

DETAILED DESCRIPTION

As previously noted, wafer testing is performed prior to dicing, whichseparates each microcircuit for packaging as an integrated circuit.Wafer testing involves a wafer probe whose probes are held in electricalcontact with solder bumps of the microelectronic devices of eachmicrocircuit in turn. A wafer probe may include vertical probes such asbuckling beam needles or may include an array of rigid probes mounted ona rigid substrate. The rigid probes may be copper and may be plated(e.g., nickel or gold plating). Unlike the compliant (i.e., individuallyflexing) vertical probes, the rigid probes are not limited in the powerthey can convey to the microelectronic devices of each microcircuit ofthe wafer. In addition, the cost of manufacturing a rigid probe deviceis relatively less than the cost of manufacturing a vertical probe card,for example. This is because the rigid probes, unlike the verticalprobes, may be fabricated using photolithography.

While rigid probes facilitate conveying more power than flexiblevertical probes, the lack of deformation in any aspect of the probedevice can create issues in sufficiently coupling to a microcircuit thatis not completely flat. According to prior approaches, a supportstructure of the wafer probe may facilitate a tilt in the rigidsubstrate to which the rigid probes are mounted based on gimbaling. Thisfacilitates matching a slope of a microcircuit to achieve an electricalcontact between the rigid probes and the solder bumps of themicrocircuit. However, such a tilt may be insufficient to couple thewafer probe to the microcircuit under test when, for example, a regionof solder bumps of the microcircuit that is not at an edge is higher orlower than solder bumps at other regions or when solder bumps onlyoccupy a portion (e.g., perimeter) of the microcircuit surface.

Embodiments of the invention relate to a compliant wafer probe assembly.On one side, the wafer probe assembly includes a compliant laminate thatholds the rigid probes that couple to the solder bumps of themicrocircuit. On an opposite side, the wafer probe assembly couples to aprinted circuit board (PCB) and the test assembly. The wafer probeassembly includes an interposer with floating pins that couple thesolder bumps of the microcircuit, via the rigid probes, to the testassembly via the PCB. As detailed, a spring plate of the wafer probeassembly facilitates alignment of the interposer to enable that couplingfrom the solder bumps to the test assembly. As also detailed, anelastomer between the laminate and interposer provides support andfacilitates regional compliance of the laminate to closely couple therigid probes to the solder bumps. According to embodiments of theinvention, the wafer probe including the spring plate and elastomer hasadvantages in facilitating a close coupling between the rigid probes andthe solder bumps by facilitating a tilt of the microcircuit, as well asregional non-planarity of the solder bumps.

FIG. 1 depicts a wafer 100 and corresponding wafer test components 130including a wafer probe assembly 200 according to one or moreembodiments of the invention. A wafer 100 can include a number ofmicrocircuits 110 that are tested in turn. A microcircuit 110 may be onthe order of 1 square-inch, for example, and is shown to include anumber of solder bumps 120 that function as contact points to test themicrocircuit 110. The wafer 100 may be supported and moved into placefor testing by a wafer prober (not shown).

A cross-sectional view of the wafer probe assembly 200 and blockdiagrams of other wafer test components 130 are shown in an explodedview. The wafer probe assembly 200 is detailed in FIG. 2 . The waferprobe assembly 200 of the wafer test components 130 acts as anelectrical and mechanical interface between the microcircuit 110 undertest and the test apparatus 150 that controls the testing. That is, thetest apparatus 150 determines and controls the test patterns that areapplied to the microcircuit 110 under test through the PCB 140 and waferprobe assembly 200.

The test apparatus 150 refers to the processor, memory, and othercomponents that control the test patterns that are implemented on eachmicrocircuit 110 under test. For example, the test apparatus 150 caninclude an automatic test pattern generator (ATPG) that applies asequence of signals to the microcircuit 110 under test via the waferprobe assembly 200. The test apparatus 150 distinguishes between correctcircuit behavior induced by the sequence of signals and faulty circuitbehavior that indicates defects in the microcircuit 110 under test. Aspreviously noted, the test apparatus 150 may connect to a PCB 140 thatcouples to the wafer probe assembly 200. The test apparatus 150 maycontrol the signals that are provided to the microcircuit 110 under testthrough the wafer probe assembly 200 and, more specifically, each rigidprobe 205. Each solder bump 120 of the microcircuit 110 is contacted anddeformed by a rigid probe 205. On an opposite side of the wafer probeassembly 200, floating pins 235 couple the wafer probe assembly 200 tothe PCB 140.

Generally, in order to perform wafer testing, the wafer 100 is moved toestablish contact between the solder bumps 120 of a microcircuit 110 andthe rigid probes 205 of the wafer probe assembly 200. In order toperform testing accurately, electrical contact must be establishedbetween each solder bump 120 of the microcircuit 110 and eachcorresponding rigid probe 205 of the wafer probe assembly 200.Specifically, each rigid probe 205 must contact and deform thecorresponding solder bump 120. A challenge to establishing sufficientcontact is the fact that the solder bumps 120 may not be completely flatbut may, instead, exhibit some non-planarity.

As previously noted, a prior approach includes using a support structurethat allows a tilt of the test components to match a tilt in themicrocircuit 110. According to one or more embodiments of the invention,the wafer probe assembly 200 facilitates not only a tilt but regionaldeformations of the solder bumps 120 on the microcircuit 110.

FIG. 2 is an exploded view of aspects of the wafer probe assembly 200according to one or more embodiments of the invention. The orientationof the wafer probe assembly 200 is upside down in FIG. 2 as comparedwith the orientation shown in FIG. 1 . The relative locations of themicrocircuit 110, on one side of the wafer probe assembly 200, and thePCB 140 and test apparatus 150 on another, opposite, side of the waferprobe assembly 200 are indicated.

The rigid probes 205 (shown in FIG. 1 ) extend from a laminate 210 and,specifically, from an inner portion 215, to couple with solder bumps 120of the microcircuit 110 under test. A land grid array (LGA) of contactpads that are not visible in FIG. 2 are on a side of the laminate 210and, specifically, the inner portion 215, opposite the side with therigid probes 205. The laminate 210 thickness is selected to balanceflexibility, which increases as thickness decreases, and strength, whichincreases as thickness increases. That is, the laminate 210 is selectedto be flexible enough such that it and, thus, the rigid probes 205conform with non-planar characteristics of the solder bumps 120. At thesame time, the laminate 210 is selected to be strong enough to supportprobing load (i.e., when the wafer probe assembly 200 is compressedagainst the microcircuit 110) as well as provide pre-load support duringformation of the wafer probe assembly 200 (i.e., when the laminate 210is put together with the interposer 230 and elastomer 220).

The floating pins 235 (shown in FIG. 1 ) are part of an interposer 230.The interposer 230 includes a pin portion 245 within a frame 240 throughwhich the floating pins 235 extend. The floating pins 235 couple to thePCB 140 on one side of the pin portion 245. On an opposite side of thepin portion 245, the floating pins 235 couple to the laminate 210, on aside of the laminate 210 that is opposite the side from which the rigidprobes 205 extend. The floating pins 235 reach the laminate 210 throughan elastomer 220. The floating pins 235 each contact a correspondingcontact pad on the side of the laminate 210 that is opposite the sidefrom which the rigid probes 205 extend to establish an electricalcontact from the rigid probes 205, which couple to solder bumps 120 ofthe microcircuit 110, through the floating pins 235 to the PCB 140.

A spring plate 250 and shim 270 are also shown as being part of thewafer probe assembly 200 in FIG. 2 . The spring plate 250 includes anouter frame 255 that is rigid and an inner frame 260 that is conformal.The laminate 210 is attached to the spring plate 250 with the interposer230 and elastomer 220 held between the laminate 210 and the spring plate250, and the floating pins 235 of the interposer 230 extend throughopenings 261 shown in the spring plate 250 and shim 270 to connect withthe PCB 140. In the exemplary embodiment shown in FIG. 2 , the holes 211of the laminate 210 match up with the holes 251 of the inner frame 260of the spring plate 250. The spring plate 250 facilitates alignment ofthe laminate 210 and the interposer 230 and, specifically, of thefloating pins 235 of the interposer 230 with corresponding contact pads(not shown) on the laminate 210. The spring plate 250 may be affixed toa stiffener 305 (FIG. 3B) by screws 360 (FIG. 3D) or other fasteners, aswell.

In addition to alignment, the spring plate 250 also facilitatescompliance. As FIG. 2 indicates, the compliant inner frame 260 of thespring plate 250 is connected to the rigid outer frame 255 only at itscorners (at connections 310 (FIG. 3A)). Thus, the inner frame 260 maytilt relative to the outer frame 255. This tilt is facilitated by theshim 270. The shim 270 is between the outer frame 255 of the springplate 250 and the PCB 140 but not between the inner frame 260 of thespring plate 250 and the PCB 140. Thus, the shim 270 results in a gap gbetween the inner frame 260 of the spring plate 250 and the PCB 140 (seee.g., FIG. 3D) that facilitates movement of the inner frame 260 relativeto the outer frame 255 based on flexibility at the connections 310. Thegap g allows the inner frame 260 to tilt and, thereby, tilt the attachedlaminate.

The elastomer 220 may be sized according to the size of the innerportion 215 of the laminate 210. Other exemplary embodiments of theelastomer 220 are discussed with reference to FIGS. 4A, 4B, and 4C. Thewafer probe assembly 200 is assembled prior to coupling with themicrocircuit 110 in a process referred to as pre-loading. In an initialstage, the spring plate 250 is attached to the shim 270, the interposer230 is attached to the PCB 140, the elastomer 220 is disposed on theinterposer 230, and the laminate 210 is attached to the spring plate250. The elastomer 220 may be selected with a compression versus loadcurve such that during this stage, the elastomer 220 is compressed to apoint beyond which the load required for further compression increasesexponentially. Alternately, the elastomer 220 may be selected such thatfurther compression at a subsequent stage is practical. In a subsequentstage, when the wafer probe assembly 200 is compressed into themicrocircuit 110 (i.e., the rigid probes 205 of the wafer probe assembly200 contact the solder bumps 120 of the microcircuit 110), the elastomer220 may provide a rigid support or facilitate compliance based on theselected elastomer 220. Flexibility in the laminate 210 is nottranslated to the interposer 230 but the floating pins 235 may absorbsome of the compliance of the laminate 210.

Exemplary characteristics of the elastomer 220 that may be consideredare thickness, elastic modulus, and size. In addition, the elastomer 220may be formed as a number of components rather than as a singlecomponent, as further discussed with reference to FIGS. 4A, 4B, and 4C.In that case, the location of the components may be determined based onareas of the laminate 210 that require the most support. For example,the microcircuit 110 may only include solder bumps 120 in certainregions. In this case, during the stage when the wafer probe assembly200 is coupled to the microcircuit 110, the laminate 210 experiencesmore load in corresponding regions (i.e., in the parts of the laminate210 that include rigid probes 205 that contact the existing solder bumps120). The elastomer 220 and the laminate 210 are designed to worktogether to ensure that all of the rigid probes 205 contact thecorresponding solder bumps 120 while preventing deformation of thelaminate 210.

FIGS. 3A, 3B, 3C, and 3D are cross-sectional views of different aspectsof the wafer test components 130. FIG. 3A is a cross-sectional view ofthe wafer probe assembly 200 according to one or more embodiments of theinvention. FIG. 3A shows two of the connections 310 between the innerframe 260 and outer frame 255 of the spring plate 250. The number ofconnections 310 between the inner frame 260 and the outer frame 255, aswell as their locations, controls the potential tilt angles of the innerframe 260 (i.e., the degrees of freedom of movement of the inner frame260 relative to the outer frame 255). In the exemplary wafer probeassembly 200 shown in FIGS. 2 and 3A, the inner frame 260 has fourconnections 310 to the outer frame 255 at the four corners of the innerframe 260. As a result, the inner frame 260 and, thus, the laminate 210that is attached to the inner frame 260, may tilt based on compressionat one or more of those connections 310. The planarization screws 350used to accomplish the tilt are discussed with reference to FIG. 3C. Theholes 211 in the laminate 210 and the holes 251 of the inner frame 260of the spring plate 250 are shown aligned. The screws 320 that affix thelaminate to the spring plate 250 via these holes 211, 251 is shown inFIG. 3B.

FIG. 3B is a cross-sectional view of the wafer probe assembly 200according to one or more embodiments of the invention. FIG. 3B shows astiffener 305 below the PCB 140. Additional stiffeners may be disposedbetween the stiffener 305 and the test apparatus 150. Two of the screws320 that affix the laminate 210 to the spring plate 250 are shown inFIG. 3B. Also shown are two of the dowels 330 that affix the outer frame255 of the spring plate 250 to the PCB 140.

FIG. 3C is a cross-sectional view of the wafer probe assembly 200according to one or more embodiments of the invention. The view in FIG.3C shows two of the dowels 340 that go through the interposer 230 to thePCB 140. The dowels 340 do not interact with the spring plate 250 but,instead, pass through the openings 261 in the spring plate 250 and shim270. FIG. 3C also shows planarization set screws 350 that pass throughthe inner frame 260 of the spring plate 250 to a surface of the PCB 140.The planarization set screws 350 may be controlled to cause a tilt inthe inner frame 260 of the spring plate 250. Specifically, as a givenplanarization set screw 350 is moved down (i.e., to push against thesurface of the PCB 140) the corresponding portion of the inner frame 260of the spring plate 250 moves up. As previously noted, this movement ofthe inner frame 260 is facilitated by a gap g between the inner frame260 and the PCB 140, which is further discussed with reference to FIG.3D.

FIG. 3D is a cross-sectional view of the wafer probe assembly 200according to one or more embodiments of the invention. FIG. 3D indicatesthe gap g between the inner frame 260 of the spring plate 250 and thePCB 140. This gap g results from the shim 270 that is only below theouter frame 255 of the spring plate 250. The gap g facilitates a slighttilt of the inner frame 260, as needed, to allow the laminate 210 toconform with a corresponding tilt at the surface of the microcircuit 110to accommodate non-planarity in the profile of the solder bumps 120.

FIGS. 4A, 4B, and 4C illustrate different arrangements of the elastomer220 according to exemplary embodiments of the invention. As FIG. 4Ashows, the elastomer 220 may be arranged around the floating pins 145 ofthe interposer 147 rather than on the floating pins 235, as shown inFIG. 3 . While the example includes elastomer 220 all around thefloating pins 235, only a portion of the frame 240 around the floatingpins 235 may be covered with elastomer 220 according to alternateembodiments of the invention.

FIG. 4B shows elastomer 220 on the floating pins 235, but oval ratherthan rectangular and off-center rather than centered on the floatingpins 235. The specific location, shape, and size of the elastomer 220may be based on the fact that one portion or side of the microcircuit110 has more solder bumps 120 than another. That is, an area of therigid probes 205 for which a higher load is required because of acorrespondence to a higher density of solder bumps 120 may dictate thatthe elastomer 220 be located on the side of the floating pins 235 thatcorresponds to the side of the higher density solder bumps 120.

FIG. 4C shows the elastomer 220 arranged as three components. Thecomponents that make up the elastomer 220 may have the same thicknessbut may have a different elastic modulus based on their location. Asshown, the different components of the elastomer 220 may also havedifferent shapes and sizes.

FIG. 5 illustrates an exemplary scenario that benefits from the waferprobe assembly according to one or more embodiments of the invention. Aset of solder bumps 120 of a microcircuit 110 and corresponding rigidprobes 205 mounted to the laminate 210 are shown. Each rigid probe 205is shown to have a cylindrical shape and to include blades 510. When themicrocircuit 110 is moved into contact with the wafer probe assembly200, the blades 510 of each rigid probe 205 contact and deform thecorresponding solder bump 120 in order to establish electrical contact.

As FIG. 5 illustrates, the solder bump profile of the microcircuit 110is non-planar. If the solder bumps 120 were evenly distributed on thesurface of the microcircuit 110 and the microcircuit 110 were tilted,then a corresponding tilt facilitated by the inner frame 260 of thespring plate 250 would be sufficient to ensure a close coupling betweenthe rigid probes 205 and the solder bumps 120. In the exemplary scenarioshown in FIG. 5 , the non-planar microcircuit 110 exhibits a dip atsolder bump 120 y. Thus, the tilt facilitated by the inner frame 260 ofthe spring plate 250 is insufficient to allow the rigid probes 205extending from the laminate 210 to conform to the solder bumps 120. Inthis case, the flexibility of the laminate 210 may allow sufficientconformity of the laminate 210 to the profile of the microcircuit 110.The elastomer 220 supports the laminate 210 to ensure that the edges ofthe laminate 210 that include rigid probes 205 x and 205 z do not deformaway from the microcircuit 110 in the exemplary scenario. Similarly, ifthe solder bump 120 y were not present, the elastomer 220 would ensurethat the load to compress the solder bumps 120 x and 120 z did notresult in sagging of the center of the laminate 210 shown in FIG. 5 .

FIG. 6 is a block diagram of aspects of the test apparatus 150. Aspreviously noted, the test apparatus 150 generates the test patternsused to test the microcircuit 110 to which the test apparatus 150 iscoupled through the test interconnect 200. The test apparatus 150includes one or more central processing units (processors) 21 a, 21 b,21 c, etc. (collectively or generically referred to as processor(s) 21and/or as processing device(s)). According to one or more embodiments ofthe present invention, each processor 21 can include a reducedinstruction set computer (RISC) microprocessor. Processors 21 arecoupled to system memory (e.g., random access memory (RAM) 24) andvarious other components via a system bus 33. Read only memory (ROM) 22is coupled to system bus 33 and can include a basic input/output system(BIOS), which controls certain basic functions of the test apparatus150.

Further illustrated are an input/output (I/O) adapter 27 and acommunications adapter 26 coupled to system bus 33. I/O adapter 27 canbe a small computer system interface (SCSI) adapter that communicateswith a hard disk 23 and/or a tape storage drive 25 or any other similarcomponent. I/O adapter 27, hard disk 23, and tape storage device 25 arecollectively referred to herein as mass storage 34. Operating system 40for execution on test apparatus 150 can be stored in mass storage 34.The RAM 22, ROM 24, and mass storage 34 are examples of memory 19 of thetest apparatus 150. A network adapter 26 interconnects system bus 33with an outside network 36 enabling the test apparatus 150 tocommunicate with other such systems.

A display (e.g., a display monitor) 35 is connected to system bus 33 bydisplay adaptor 32, which can include a graphics adapter to improve theperformance of graphics intensive applications and a video controller.According to one or more embodiments of the present invention, adapters26, 27, and/or 32 can be connected to one or more I/O busses that areconnected to system bus 33 via an intermediate bus bridge (not shown).Suitable I/O buses for connecting peripheral devices such as hard diskcontrollers, network adapters, and graphics adapters typically includecommon protocols, such as the Peripheral Component Interconnect (PCI).Additional input/output devices are shown as connected to system bus 33via user interface adapter 28 and display adapter 32. A keyboard 29,mouse 30, and speaker 31 can be interconnected to system bus 33 via userinterface adapter 28, which can include, for example, a Super I/O chipintegrating multiple device adapters into a single integrated circuit.

According to one or more embodiments of the present invention, the testapparatus 150 includes a graphics processing unit 37. Graphicsprocessing unit 37 is a specialized electronic circuit designed tomanipulate and alter memory to accelerate the creation of images in aframe buffer intended for output to a display. In general, graphicsprocessing unit 37 is very efficient at manipulating computer graphicsand image processing and has a highly parallel structure that makes itmore effective than general-purpose CPUs for algorithms where processingof large blocks of data is done in parallel.

Thus, as configured herein, the test apparatus 150 includes processingcapability in the form of processors 21, storage capability includingsystem memory (e.g., RAM 22), and mass storage 34, input means such askeyboard 29 and mouse 30, and output capability including speaker 31 anddisplay 35. According to one or more embodiments of the presentinvention, a portion of system memory (e.g., RAM 24) and mass storage 34collectively store an operating system such as the AIX® operating systemfrom IBM Corporation to coordinate the functions of the variouscomponents shown in the test apparatus 150.

Various embodiments of the invention are described herein with referenceto the related drawings. Alternative embodiments of the invention can bedevised without departing from the scope of this invention. Variousconnections and positional relationships (e.g., over, below, adjacent,etc.) are set forth between elements in the following description and inthe drawings. These connections and/or positional relationships, unlessspecified otherwise, can be direct or indirect, and the presentinvention is not intended to be limiting in this respect. Accordingly, acoupling of entities can refer to either a direct or an indirectcoupling, and a positional relationship between entities can be a director indirect positional relationship. Moreover, the various tasks andprocess steps described herein can be incorporated into a morecomprehensive procedure or process having additional steps orfunctionality not described in detail herein.

One or more of the methods described herein can be implemented with anyor a combination of the following technologies, which are each wellknown in the art: a discrete logic circuit(s) having logic gates forimplementing logic functions upon data signals, an application specificintegrated circuit (ASIC) having appropriate combinational logic gates,a programmable gate array(s) (PGA), a field programmable gate array(FPGA), etc

For the sake of brevity, conventional techniques related to making andusing aspects of the invention may or may not be described in detailherein. In particular, various aspects of computing systems and specificcomputer programs to implement the various technical features describedherein are well known. Accordingly, in the interest of brevity, manyconventional implementation details are only mentioned briefly herein orare omitted entirely without providing the well-known system and/orprocess details.

In some embodiments, various functions or acts can take place at a givenlocation and/or in connection with the operation of one or moreapparatuses or systems. In some embodiments, a portion of a givenfunction or act can be performed at a first device or location, and theremainder of the function or act can be performed at one or moreadditional devices or locations.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises” and/or “comprising,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, element components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thepresent disclosure has been presented for purposes of illustration anddescription, but is not intended to be exhaustive or limited to the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art without departing from the scope and spiritof the disclosure. The embodiments were chosen and described in order tobest explain the principles of the disclosure and the practicalapplication, and to enable others of ordinary skill in the art tounderstand the disclosure for various embodiments with variousmodifications as are suited to the particular use contemplated.

The diagrams depicted herein are illustrative. There can be manyvariations to the diagram or the steps (or operations) described thereinwithout departing from the spirit of the disclosure. For instance, theactions can be performed in a differing order or actions can be added,deleted or modified. Also, the term “coupled” describes having a signalpath between two elements and does not imply a direct connection betweenthe elements with no intervening elements/connections therebetween. Allof these variations are considered a part of the present disclosure.

The following definitions and abbreviations are to be used for theinterpretation of the claims and the specification. As used herein, theterms “comprises,” “comprising,” “includes,” “including,” “has,”“having,” “contains” or “containing,” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, acomposition, a mixture, process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but can include other elements not expressly listed or inherentto such composition, mixture, process, method, article, or apparatus.

Additionally, the term “exemplary” is used herein to mean “serving as anexample, instance or illustration.” Any embodiment or design describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs. The terms “at least one”and “one or more” are understood to include any integer number greaterthan or equal to one, i.e. one, two, three, four, etc. The terms “aplurality” are understood to include any integer number greater than orequal to two, i.e. two, three, four, five, etc. The term “connection”can include both an indirect “connection” and a direct “connection.”

The terms “about,” “substantially,” “approximately,” and variationsthereof, are intended to include the degree of error associated withmeasurement of the particular quantity based upon the equipmentavailable at the time of filing the application. For example, “about”can include a range of ±8% or 5%, or 2% of a given value.

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instruction by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdescribed herein.

What is claimed is:
 1. A wafer test device comprising: a conformallaminate; rigid probes extending from the laminate and configured toform an electrical connection with a microcircuit under test; a springplate on a side of the laminate that is opposite a side from which therigid probes extend, wherein the laminate is attached to the springplate; and an interposer on the side of the laminate that is oppositethe side from which the rigid probes extend, the interposer including apin portion within a frame.
 2. The device according to claim 1, whereina number and locations of connections between the inner frame and theouter frame of the spring plate are configured to control degrees offreedom of movement of the inner frame relative to the outer frame. 3.The device according to claim 1, further comprising floating pinsextending from the pin portion of the interposer.
 4. The deviceaccording to claim 3, wherein the floating pins contact the laminate onthe side of the laminate that is opposite the side from which the rigidprobes extend.
 5. The device according to claim 3, wherein the floatingpins extend through an opening in the inner frame of the spring plateand are configured to contact a printed circuit board (PCB).
 6. Thedevice according to claim 5, wherein the floating pins are configured toconvey electrical signals from a test apparatus coupled to the PCB tothe laminate and through the rigid probes to the microcircuit undertest.
 7. The device according to claim 5, further comprising a shimbetween the outer frame of the spring plate and the PCB configured tocreate a gap between the inner frame of the spring plate and the PCB. 8.The device according to claim 3, further comprising an elastomerdisposed between the laminate and the interposer.
 9. The deviceaccording to claim 8, wherein the floating pins extend through theelastomer to the laminate.
 10. The device according to claim 8, whereinthe elastomer is configured with an elastic modulus, size, shape, andlocation to prevent deformation of the laminate while allowing regionalcompliance of the elastomer during a process of connecting the rigidprobes to the microcircuit.
 11. The device according to claim 10,wherein the elastomer is configured as two or more components.
 12. Amethod of assembling a wafer test device, the method comprising:assembling a conformal laminate with rigid probes extending from thelaminate to form an electrical connection with a microcircuit undertest; arranging a spring plate on a side of the laminate that isopposite a side from which the rigid probes extend, and attaching thelaminate to the spring plate; and disposing an interposer on the side ofthe laminate that is opposite the side from which the rigid probesextend, the interposer including a pin portion within a frame.
 13. Themethod according to claim 12, further comprising selecting a number andlocations of connections between the inner frame and the outer frame ofthe spring plate to control degrees of freedom of movement of the innerframe relative to the outer frame.
 14. The method according to claim 12,further comprising arranging floating pins to extend from the pinportion of the interposer.
 15. The method according to claim 14, whereinthe arranging the floating pins includes the floating pins contactingthe laminate on the side of the laminate that is opposite the side fromwhich the rigid probes extend.
 16. The method according to claim 14,wherein the arranging the floating pins includes the floating pinsextending through an opening in the inner frame of the spring plate tocontact a printed circuit board (PCB).
 17. The method according to claim16, wherein the arranging the floating pins includes configuring thefloating pins to convey electrical signals from a test apparatus coupledto the PCB to the laminate and through the rigid probes to themicrocircuit under test.
 18. The method according to claim 16, furthercomprising disposing a shim between the outer frame of the spring plateand the PCB to create a gap between the inner frame of the spring plateand the PCB.
 19. The method according to claim 14, further comprisingdisposing an elastomer between the laminate and the interposer.
 20. Themethod according to claim 19, wherein the arranging the floating pinsincludes the floating pins extending through the elastomer to thelaminate.
 21. The method according to claim 19, wherein the disposingthe elastomer includes configuring the elastomer with an elasticmodulus, size, shape, and location to prevent deformation of thelaminate while allowing regional compliance of the elastomer during aprocess of connecting the rigid probes to the microcircuit.
 22. Themethod according to claim 21, wherein the disposing the elastomer is astwo or more components.